The present invention relates to selectively etching a tungsten (W) containing layer during the production of a semiconductor device.
During semiconductor wafer processing, features may be etched through a tungsten containing layer.
During the formation of certain features with tungsten, the tungsten must be selectively etched, while silicon, silicon oxide, silicon oxynitride, silicon nitride, or titanium nitride is minimally etched. Previously, such selectivity could not be accomplished.